For the FAB-MS analysis, all experiments were performed on a JEOL SX/SX102A tandem four-sector mass spectrometer operated at 10 kV accelerating potential. Ions were produced by fast atom bombardment with xenon using a JEOL FAB gun operated at 6 kV. The spectra were recorded in the positive ion mode with a resolution of approximately 1000 (90% valley). The spectra are averaged profile data of two scans as recorded by a JEOL complement data system. These spectra were acquired from 100 to 2500 m/z at a rate that would scan from m/z 100 to m/z 2500 in 1 minute with a filtering rate of 300 Hz.